Owing to the worldwide concentration on energy security,
a recent
trend of the energy mix is adopted by gradually replacing fossil fuels
with other renewable energy sources. Biodiesel has emerged as a promising
candidate. It is renewable, nontoxic, and biodegradable and can be
a suitable choice for undertaking this energy issue. Biodiesel can
be produced via various procedures, e.g., dilution, microemulsion,
pyrolysis, and transesterification. The latter is the most utilized
procedure given its effectiveness in which vegetable oils or animal
fats and short-chain alcohols are allowed to react in the presence
of a catalyst. Different oil feedstocks are identified including edible,
nonedible, and algae-based biomass resources. Conventionally, homogeneous
catalysts are generalized for biodiesel production because of their
high catalytic activity and low cost, albeit, due to high wastewater
generation during the purification process of the product, separation
problems, and soap production, heterogeneous catalysts have emerged
to overcome problems facing the homogeneous catalytic system. Of these,
magnetic nanomaterials including magnetite and spinel ferrites are
introduced. A literature survey is comprehended in this review concerning
magnetic nanocatalysts, preparation methods, and applications. The
economic lookout is portrayed by using magnetic catalysts as a future
catalytic vision. Besides, the biodiesel’s physicochemical
properties including kinematic viscosity, density, cetane number,
flash, pour, and cloud points are reviewed for its commercial utilization.